Python VS extension: debug fails when Debug console is already opened

Description

I found an issue when debugging in Theia v0.15.0 with Python VS extension. After version 2019.9.34911 there is an error when starting a debug session with the "Python Debug Console" already open.

Reproduction Steps

Python VS extension : 2020.1.58038

OS and Theia version: Ubuntu Disco and Theia v0.15.0. Installation with this Dockerfile. Using the following package.json

Diagnostics: In the Python Debug console:

~/workspace# /usr/bin/python /tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/launcher /root/workspace/example.py
Traceback (most recent call last):
File "/usr/lib/python3.7/runpy.py", line 193, in _run_module_as_main
 "__main__", mod_spec)
File "/usr/lib/python3.7/runpy.py", line 85, in _run_code
 exec(code, run_globals)
File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/launcher/__main__.py", line 80, in <module>
 main()
File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/launcher/__main__.py", line 42, in main
 launcher.connect(launcher_port)
File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/launcher/../../ptvsd/launcher/__init__.py", line 27, in connect
 sock.connect(("127.0.0.1", launcher_port))
ConnectionRefusedError: [Errno 111] Connection refused

In the backend:

root ERROR [hosted-plugin: 111] E+00010.052: /handling #2 request "launch" from IDE[1]/
          Handler 'IDE._start_message_handler.<locals>.handle' (file '/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/components.py', line 160)
          couldn't handle #2 request "launch" from IDE[1]:
          Traceback (most recent call last):
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/common/messaging.py", line 766, in _handle
              result = handler(self)
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/components.py", line 95, in lock_and_handle
              return f(self, message)
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/ide.py", line 176, in handle
              f(self, request)
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/ide.py", line 278, in launch_request
              self.session, request, sudo, args, console, console_title
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/launchers.py", line 115, in spawn_debuggee
              spawn_launcher()
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/launchers.py", line 98, in spawn_launcher
              "env": env,
            File "/usr/lib/python3.7/contextlib.py", line 119, in __exit__
              next(self.gen)
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/adapter/sessions.py", line 163, in _accept_connection_from
              sock, (other_host, other_port) = listener.accept()
            File "/usr/lib/python3.7/socket.py", line 212, in accept
              fd, addr = self._accept()
          socket.timeout: timed out
          Stack where logged:
            File "/usr/lib/python3.7/threading.py", line 885, in _bootstrap
              self._bootstrap_inner()
            File "/usr/lib/python3.7/threading.py", line 917, in _bootstrap_inner
              self.run()
            File "/usr/lib/python3.7/threading.py", line 865, in run
              self._target(*self._args, **self._kwargs)
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/common/messaging.py", line 1523, in _run_handlers
              handler()
            File "/tmp/vscode-unpacked/ms-python.python-latest.vsix/extension/pythonFiles/lib/python/new_ptvsd/wheels/ptvsd/adapter/../../ptvsd/common/messaging.py", line 812, in _handle
              self.describe(),